Refactor POST handling.

- Split into admin and user handlers, each admin page gets its own file now
- Enforce role access once for admin POST requests
- Automatically load POST logic for admin-based requests based on the referring page, otherwise automatically load all user request logic
- Add support for using custom POST handlers

post/admin/admin_settings_localization.php

@@ -0,0 +1,22 @@
+<?php
+
+if (isset($_POST['edit_localization'])) {
+
+    validateCSRFToken($_POST['csrf_token']);
+
+    $locale = sanitizeInput($_POST['locale']);
+    $currency_code = sanitizeInput($_POST['currency_code']);
+    $timezone = sanitizeInput($_POST['timezone']);
+
+    mysqli_query($mysqli,"UPDATE companies SET company_locale = '$locale', company_currency = '$currency_code' WHERE company_id = 1");
+
+    mysqli_query($mysqli,"UPDATE settings SET config_timezone = '$timezone' WHERE company_id = 1");
+
+    //Logging
+    mysqli_query($mysqli,"INSERT INTO logs SET log_type = 'Company', log_action = 'Edit', log_description = '$session_name edited company localization settings', log_ip = '$session_ip', log_user_agent = '$session_user_agent', log_user_id = $session_user_id");
+
+    $_SESSION['alert_message'] = "Company localization updated";
+
+    header("Location: " . $_SERVER["HTTP_REFERER"]);
+
+}